Conventional foldable children's playpens include a foldable frame assembly. The folding portions of such foldable frame assembly are mostly disposed on the upper ends of peripheral walls and the chassis of the playpen. Foldable upper frame assemblies of children's playpens are disclosed in U.S. Pat. Nos. 4,357,735; 4,070,716; 4,044,411; 4,573,224; 4,376,318; 4,069,524; 4,811,437; etc. Foldable chassis frame assemblies of children's playpens are disclosed in U.S. Pat. Nos. 4,703,505; 4,538,309; 4,008,499; 4,688,280; 4,811,437, etc.
In the above-mentioned U.S. Pat. Nos. 4,811,437 includes both the foldable upper and lower assemblies. However, two drawbacks exist in this U.S. Pat. No. 4,811,437 as follows:
1. The folding mechanism of the upper frame assembly thereof includes multiple components such that the assembling procedure is complicated and the manufacturing cost is high.
2. The folding mechanism of the chassis includes six support legs diverging radially outwardly. However, four inner panels of the children's playpen are connected and two L-shaped connectors of a middle transverse rail of the chassis are located at the central connecting portions between the inner panels. Consequently, no appropriate supporting force can be provided and safety cannot be insured.